US3448789A

US3448789A - Starter bar for continous metal casting apparatus

Info

Publication number: US3448789A
Application number: US616103A
Authority: US
Inventors: Francis Gallucci
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1967-02-14
Filing date: 1967-02-14
Publication date: 1969-06-10
Anticipated expiration: 1986-06-10
Also published as: NL6801973A; DE1608089A1; NL160185C; AT301067B; FR1553514A; GB1216103A; DE1608089B2; BE710548A; NL160185B; ES350293A1

Description

F. GALLUCCI `Iune l0, 1969 STARTER BAR FOR CONTINUOUS METAL CASTING APPARATUS l Filed Feb. 14, 1967 Sheet of 3 U/ C U Ru OA MG WS Nm ...N A R F M ma ATTORNEY F. GALLUCCI June l0, 1969 STARTER BAR FOR CONTINUOUS METAL CASTING APPARATUS sheet 3 'Filed Feb. 14, 196'? INVENTOR www" FRANCIS GALLUCCI ATTORNEY June l0, 1969 F. GALLuccl 3,448,789

STARTER BAR FOR CONTINUOUS METAL CASTING APPARATUS Filed Feb. 14, 1967 sheet 5 of 3 FRANCIS GLLUCCI SYM ATTORNEY United States Patent O 3,448,789 STARTER BAR FOR CONTINUOUS METAL CASTING APPARATUS Francis Gallucci, North Huntington Township, Westmoreland County, Pa., assignor to United States Steel Corporation, a corporation of Delaware Filed Feb. 14, 1967, Ser. No. 616,103 Int. Cl. B22d 11/08, 27/04 U.S. Cl. 164-274 10 Claims ABSTRACT OF THE DISCLOSURE A starter bar for a continuous metal casting apparatus. The starter lbar has a detachable chill plate which abuts the lower end of a casting and is secured' to the casting by pins which become embedded in the casting during solidification. The slide plate positioned within the starter bar to releasably engage the pins on the chill plate is actuated by a plunger rod passing vertically through the starter bar. Actuation of the plunger rod is accomplished by the traveling basket carrying the starter =bar away from the casting.

This invention relates to a starter bar for continuous metal casting apparatus and more particularly to detachable starter bars for continuous steel casting apparatus.

In the continuous casting of steel, molten steel is teemed into the upper end of an open-ended tubular water-cooled continuous casting mold which is closed olf at the lower end by means of a starter bar. The starter bar allows solidification of the steel to begin in the mold with the formation of a thin solid metal shell around the mold walls and along the upper surface of the starter bar while a core of metal in the center of the mold remains in the molten state. The starter bar generally has means on its upper surface for forming an interlocking grip with this solidified shell. When the height of molten metal in the mold reaches a predetermined level, the starter bar and the attached partially solidified casting are lowered under the control of motor driven pinch rolls located at a substantial distance below the mold. As the casting decends below the mold, it is further cooled, and solidication continues to take place.

According to one mode of operation, solidification of the casting is still incomplete at the time when the casting passes through the pinch rolls. The advantage of this mode of operation is that a smaller height of casting apparatus is required than would be necessary if solidilication were completed before the casting descends to the pinch rolls.

After the starter bar descends below the pinch rolls, the starter fbar is disconnected from the casting and is lowered on a vertically traveling basket which travels faster than the casting. The casting may then be deflected in a lateral direction.

Because the casting has a liquid core that passes through the pinch rolls, it is necessary to separate the starter :bar from the casting in some way that does not require sawing or other rupturing of the casting. One way in which the starter bar and the casting can be separated is to provide a detachable chill plate on the top surface of the starter lbar and a means for detaching the chill plate from the starter bar when the casting reaches the pinch rolls. The starter bar may then be lowered vertically on the aforesaid traveling basket, while the chill plate and' the attached casting are deilected laterally.

Heretofore, detachment of the chill plate in the casting from the starter bar has Ibeen accomplished by means "ice of a striker element located exteriorly of the starter bar at an elevation where disconnection of the starter bar from the casting is desired. This striker element has been used to strike a movable release element within the starter bar head to cause t-he starter bar to [be released from the chill plate and attached casting. The striker element in this apparatus has been set into motion lb-y la sensing mechanism which determines when the starter -bar has reached the predetermined elevation for (disconnection of the chill plate.

Although the aforesaid apparatus is capable of disconnecting the starter bar from the chill plate and attached casting swithout severing the casting, it has the disadvantage of requiring a relatively complex system for accomplishing its objective.

Accordingly, it is an object of this invention to provide a starter bar having a detachable chill plate and a simple mechanical means for detaching the chill plate from the starter bar when the predetermined elevation for disconnection is reached.

It is another object of the invention to detach a starter bar from a chill plate in a continuously moving casting without mechanical severance of the casting.

It is another object of the invention to detach a starter bar from a chill plate embedded in a continuously moving casting upon actuation of a plunger rod therein by a traveling basket below the starter Ibar.

These and other objects will be apparent from the specication which follows.

According to the present invention, a novel starter bar is provided for use in continuous metal casting apparatus having pinch rolls for controlling the rate of descent of the casting and a vertically traveling basket for removing the starter bar after it has been disconnected from the casting. This novel starter bar comprises a chill plate, a slide plate located within a hollow portion of the head of the starter 'bar for releasably securing the chill plate and the starter bar together, and 'a plunger connected to the slide plate through a pivot linkage and extending through a bore in the starter bar to a point below the lower end of the starter bar. As the starter bar descends, this plunger -will strike the aforesaid traveling basket and be moved upwardly, releasing the chill plate from the starter .bar by moving the slide plate to` a position in rwhich such release takes place.

This invetnion will now :be described in detail with reference to the accompanying drawings in which:

FIG. 1 is an elevational view of a starter bar according to this invention;

FIG. 2 is an enlarged view of the starter bar head showing in detail the means for securing the starter bar and chill plate together;

FIG. 3 is an elevational view with parts shown in section taken along line 3 3 of FIG. 2, showing a portion of the side plate which secures the starter bar and chill plate together;

FIG. 4 is a plan view of a chill plate of this invention, with parts broken away;

FIG. 5 is a vertical sectional view, taken along line 5 5 of FIG. 4; and

FIG. 6 is a diagrammatic view of a continuous casting apparatus in which the starter bar of the present invention may be used.

Referring to FIGS. l and 2, starter b'ar 10 has an elongated metal body portion 11 `formed of interlocked sections 1`1a, 11b and having a longitudinal rectangular opening 12 extending Ialong the central axis thereof, and a head 13 at the upper end of the starter bar. The sections may be locked together, for example, by intertting tongues and grooves and conventional locking means. The head 13 has a hollow interior recess 14 within which a slide plate 15 is positioned to slide laterally. The slide plate 15 is supported, for example, by means of antifrietion rollers 16 (FIG. 2) which are conveniently journalled in the starter head 13 and has a plurality of keyhole slots 17 passing vertically therethrough (see FIG. 3). Each slot 17 has a round portion and an elongated portion of narrower width than the .diameter of the round portion. A plurality of pins 18 extend through the slots 17 and through the top 19 of the starter bar head 13 and terminate in heads 20 which form an interlocking grip with the solidilied casting as the latter freezes. The pins 18 each include a main body portion 21 of a diameter greater than the elongated portion of a slot 17 and slightly smaller than the round portion of the slot, and a neck portion 22 within the body portion 21 which is of smaller diameter than the width of the elongated portion of the slot. The pins 18 are secured to a chill plate 23 which rests on the upper end of starter bar 10. In one position of the slide plate 15, the main body portion 21 of pins 18 yabut the slide plate at the elongated portions of slot 17 with the neck portions 22 within the elongated portions so that the pins 18 prevent detachment of the chill plate 23 from the starter bar 10. When the slide plate 15 is moved to the other of its positions, the main body portions 21 of pins 18 are in alignment with the round portions of the slots 17 to slide therethrough and thereby permit detachment of the starter bar from the chill plate.

An elongated plunger rod 24 which terminates at its lower end in a plunger 25 (FIG. 1) is vertically disposed in the opening 12 of the starter bar in reciprocal relation. A plurality of bronze bushings 26 is provided in the bore 12 to slidably guide the plunger rod 24 and a well 27 is formed at the lower end of the starter bar 10 to receive plunger 25. The plunger 25 is dimensioned with respect to the lower end of starter bar and well 27 to extend below the starter bar when in its lowermost position.

The slide plate is connected to plunger 4rod 24 by means of a pivot linkage which has a link 28 pivotally secured to the plunger rod 24 at one end and pivotally secured at an ear 29 secured to the underside of the slide plate 15 at the other end.

The slide plate 15 is shown in FIG. 2 in the position permitting release of the starter bar 10` from the chill plate 23. The dotted line position of link 28 and of ear 29 indicates the positions of these members when the slide plate 15 is in locking engagement with pins 18. The weight of plunger rod 24 acting through link 28 tends to move the slide plate 15 towards the dotted line pinlocking position.

A spring pressed latch 30 is pivotally mounted in recess 14 for preventing inadvertent moving of the slide plate 15 toward the pin-locking position not only during assembly of the starter bar 10 but also after the slide plate 15 has been moved to the pin unlocking position during descent of the starter bar.

Referring to FIGS. 4 and 5, the chill plate 23 has at least Aone upstanding cylindrical splash shield 31 having a plurality of holes 34 in the side walls which is adapted to receive molten steel therein so as to protect the pins, 18 from splashing steel when pouring is initiated into the shield 31. In addition, the chill plate 23 also has a plurality of openings 32 to receive pins 18 in a locking relation which is facilitated by cut-out tanks around the openings.

Referring to FIG. 6, in operation, prior to the start of the casting, the starter -bar head 13 is attached to the starter bar body 11 by means of bolts 33 (FIG. 2). The starter bar 10 is then moved upwardly so that the top 19 of the starter bar is in the lower portion of the openended continuous casting mold 35. lThe chill plate 23 is next placed on top of the starter bar head 13, and the pins 18 are then put in place while slide plate 15 is retained Iby latch 30 in the pin unlocking position. The last pin 18a to be put in place contacts the latch 30 and forces the latch 30 to move downwardly so that it is out of contact with the abutment 36. This permits slide plate 15 to be moved by the weight of the plunger rod under gravity to the pin-locking position. The starter bar is then ready for a casting.

Molten metal is then teemed from a vessel 37 into the upper end of mold 35 and cooling is initiated. After a thin shell of solid metal has formed the casting descends in a path as shown by dotted lines and indicated as numeral 38. The casting is then guided by guide rollers 39 and simultaneously cooled as it descends. Pinch rolls 40 located at a considerable distance below mold 35 control the rate of descent of the casting. Initially these pinch rolls, which are motor driven, engage the starter bar 10, and after the starter bar 10` descends below the pinch rolls 40, these pinch rolls directly engage the casting.

After the starter bar 10 descends below pinch rolls 40, it continues its vertical descent until the plunger 25 contacts a traveling basket 41 in its path which initially is in the uppermost position shown in dotted lines in FIG. 6. As the starter bar 10 and attached casting further descend, the traveling basket 41 remains stationary and the plunger 25 and plunger rod 24 are pushed upwardly to cause movement of the slide plate 15 toward the pin unlocking position shown in solid lines in FIG. 2. This aligns the round portions of slot 17 with pins 18, so that the starter bar 10 can move vertically away from the chill plate 23 and the attached casting. The traveling basket 41 is then caused to descend in a vertical path at a speed greater than the casting speed which may be accomplished by means known in the art in order to move the starter bar from the detached chill plate. The traveling basket conveys the starter bar 10 downwardly to a predetermined location at the lower end of travel of basket 41 (shown in solid lines in FIG. 6), where the starter bar may be lowered to a horizontal position and stowed as is well known in the art. Meanwhile, after the casting and chill plate 23 have been disconnected from the starter bar 10, they are deected into a curved path. A curved guide roll rack 42 located below pinch rolls 40 may be used to guide the casting in this curved path. Rack 42 is shown in a retracted position in FIG. 6 which allows the starter bar to travel vertically.

The above operation is repeated after a casting operation has been completed and a subsequent casting operation is to be initiated.

The starter bar of this invention is a novel and simple structure which permits disconnection of the starter bar from the chill plate and attached casting by simple mechanical means, not requiring the use of any apparatus elements not ordinarily found in continuous casting apparatus. The complex starter bar disconnecting mechanism previously referred to! are dispensed with according to lthe teachings of this invention.

Having thus described the invention, it is not intended that it be so limited as changes may be readily made therein without dep'arting lfrom the scope of the invention. Accordingly, it is intended that the subject matter described above and shown in the drawings be interpreted as illustrative and not in a limiting sense.

Having now described my invention, l claim:

1. A starter bar for a continuous metal casting apparatus, said starter bar comprising an elongated metal body having a longitudinal opening extending therethrough, '-a chill plate, release means for releasably securing said chill plate to one end of said body, a longitudinally movable plunger rod in said opening connected to said release means for actuating said release means and having an end extending exteriorly of said starter bar whereby said end of said plunger rod is adapted to engage an accelerating member located exteriorly of said starter bar to move said plunger longitudinally to actuate said release means to release said chill plate from said starter bar when said starter bar reaches a predetermined elevation in its descent.

2. Apparatus according to claim 1 in which said release means includes a horizontally movable slide plate.

3. Apparatus according to claim 2 in Which said release means further includes pins attached to said chill plate for gripping a casting during solidification, said pins including neck portions, said slide plate including keyhole slots for enveloping said neck portions to prevent disconnection of said starter bar from said chill plate until the predetermined elevation is reached.

4. Apparatus as set forth in claim 3 in which a pivotal linkage connects said plunger rod to said slide plate whereby said slide plate is movable between a pin locking position and a pin unlocking position.

5. Apparatus as set (forth in claim -3 in which a latch is pivotally mounted in said end of said metal body to releasably lock said slide plate in a pin unlocking position, said latch being pivotally movable upon attachment of a predetermined pin in said chill plate to permitv movement of said slide plate into a pin locking position with,

respect to said pins.

6. Apparatus as set forth in claim 1 in which said chill plate includes at least one upstanding splash shield thereon for receiving molten metal therein, said splash shield having a plurality of openings in the sidewalls thereof for passage of molten metal therethrough.

7. In la continuous casting apparatus including a tubular mold in which a casting is formed, pinch rolls below said mold for moving the rformed casting in a vertical path at a controlled rate of descent, and a traveling basket below said pinch rolls for movement in a vertical path; the improvement comprising a starter bar having an enlongated metal body having a longitudinal opening extending therethrough, a chill plate detachably secured to the upper end of said starter bar, release means for detachably securing said chill plate and said starter bar together,` la longitudinally movable plunger rod in said opening connected to said release means and having an end extending ex-teriorly of the lower end of said starter bar for engaging said traveling basket at a predetermined elevation in the path of descent of said starter bar, said traveling basket moving said plunger upwardly upon enga-gement to thereby release said chill plate from said starter bar. l

8. Apparatus as set forth in claim 7 in which 'a rack is positioned above said traveling basket to guide a casting and attached chill plate out of the path of travel of s'aid traveling basket.

9. Apparatus as set lforth in claim 7 in 'which said release means includes a slide plate journalled in said body and connected to said plunger rod for horizontal movement relative thereto upon vertical movement of said plunger rod, said slide plate having a plurality off slots therein, and a plurality of pins attached to said chill plate, each pin having a neck portion received in a respective slot of said slide plate to detachably lock said chill plate to said slide plate.

10. Apparatus as set forth in claim 7 in which said chill plate includes at least one upstanding splash shield for receiving molten metal therein, said splash shield having a Iplurality of openings in the side walls thereof for passage of molten me-tal therethrough.

References Cited UNITED STATES PATENTS 3,338,297 8/ 1967 Foldessy 164-274 FOREIGN PATENTS 1,319,964 10/ 1962 France.

929,478 6/ 1963 Great Britain. 945,970 1/ 1964 Great Britain. 982,981 2/ 1965 Great Britain.

I. SPENCER OVERHOLSER, Primary Examiner.

R. SPENCER AN NEAlR, Assistant Examiner.